1. Field
Example embodiments relate to method of operating an inverter.
2. Description of the Related Art
In semiconductor integrated circuits, e.g., dynamic random access memories (DRAMs), static random access memories (SRAMs), non-volatile memories, liquid crystal display (LCD) devices, and organic light emitting devices, various logic circuits, for example, NAND (not and) and NOR (not or) circuits, are used. An inverter is a basic component of logic circuits.
In general, a Si-based inverter is a complementary metal-oxide semiconductor (CMOS) inverter including both an n-channel metal-oxide semiconductor (NMOS) transistor and a p-channel metal-oxide semiconductor (PMOS) transistor. When a Si layer is used as a channel layer, the NMOS or PMOS transistor may be more easily formed by varying the type of doping elements used for the channel layer, and thus, a CMOS inverter may be easily manufactured. For example, a p-channel layer is formed by doping a Si layer with a Group III element, e.g., boron (B).
However, when a channel layer is formed using an oxide semiconductor, manufacturing a p-channel layer due to the characteristics of the material of the oxide semiconductor may be difficult. That is, channel layers formed using an oxide semiconductor are usually n-channel layers. Accordingly, when using a transistor having a channel layer formed of an oxide semiconductor, realizing an inverter having both an n-channel transistor and a p-channel transistor may be difficult.